I’m in a 14 team keeper league, currently 7th. You can keep almost your entire roster year to year so talent does not ever change hands. Top 6 go to playoffs so I’m right on the edge and trying to move pieces for next season. I was recently offered a trade of Daniel Murphy for Carlos Rodon. My pitching staff is weak: Gibson, Leblanc, Anderson, Happ, Manaea, Maeda, Quintana and Pomeranz. My back-up at 2B is J Wendle. I’m trying to prep for future seasons so do I pull the trigger? Who holds more long term value?

If you want me to look at your team, post the team. Don't post a link to another site where the team is.
Have you given me all the info I need to judge your team? The number of teams in the league is a good start for the big overall questions.
Is your league H2H? Roto?
I don't know who's on your waivers. Don't just ask me who you should pick up. Give me names to choose from.
If you only have one team, post your team in your signature with the league parameters.
I don't know every single matchup for next week, so if you want me to choose a player for the following week and you think the matchups are important, tell me who they're facing.
There's more than one player with the same last name? Then spell out who you're talking about.
Thanks!